NOTES ON THE GENUS OEPHALEUTHERUS OF KAFI- 

 NESQUE, AND OTHER RAYS WITH ABERRANT PECTORAL 

 FINS (PROPTERYGIA AND HIEROPTERA). 



By Theodore Gill, LL. D. 



In a recent article on '' The Nomenclature of the Myliobatidic or 

 Aetobatidit^," I retained the names MyUohaUs and A'etohntis with a pro- 

 viso. Adopting temporarily the views of Agassiz, 1 remarked: 



This, it seems to nie, is a perfectly legitimate view aucl use of the two names. 

 P>oth names, Ai'tobafiis and My liobat is, might have beeu retained for ditterent sections 

 of the old genus, if no other considerations had forbidden. Both of those names, 

 however, as President Jordan has reminded me, were anticipated by a name given 

 by Rafinesque in 1810. 



CEPIIALEUTIIKUUS. 



Rafinesque, in his " Indice d'lttiologi;; Siciliaua," has the genus Cephaleuiherua 

 interposed between his Mohuhi, ( = Cephaloptera Uiim.) and Uroxis {Trygon auct.), 

 which, according to Dr. Jordan, is a Myliobalis. It is not, however, mentioned by 

 Doderlein in his very fall synonyms of the MyUobatids of the Mediterraneau, and 

 the book in question can not be found. While 1 have little doubt that Y>v. Jordan 

 is correct in his identification, and that the name Ceplialeuthenis should be taken for 

 Myliobatis, I defer doing so until I am able to consult the "Indice" or a copy of it. 

 Meanwhile I retain the name Myliobati.s, but adojit for the family Aetobatichv. 



Since that publication, Dr. Jordan kindly sent me a copy of the 

 description of CepJialeutJierun, und the "Indice d'lttiologia Siciliana" 

 was found. These data have compelled me to refuse to adopt Cepha- 

 leutherns as a substitute for MyUobutis, and led me to consider that 

 nominal genus to have been based on a teratologic specimen exhibit- 

 ing an arrest of development. Ratiuesque's description follows: 



Gen. Cephalcuthcrus. Capo sciolto, e diviso dall' ale laterali, occhi, e'spiragli uniti, 

 e situati al lato del capo, due ale sopra la coda, nessuua alia sua estremitii. Oaserv. 

 Questo genere e rimarchevolissimo, a motivo del carattere che oiferi^ce il suo capo 

 sciolto, il quale <■ unito all' ale laterali o.ssiauo pettorali, in tutti gli Jiltri generi 

 viciui. 



Sp. n. Ceplialeuthenis maciilatas. Fulvastro al disopra con delle macchie fosche, 



bianchiccio al di sotto, capo appuntato, ale laterali anteriori, appuntate, e scabre 



anceriormente, un ordine di spine sopra la Schiena, e tre sopra la coda, che 6 acuta. 



Osserr. H:l alcuue spine disposte regolarmente sopra il capo, e dietro *gli occhi, la 



bocca c sitnata sotto il capo, ed in un fosso, e le aperture brauchiali sono sotro la 



Proceedings of the United States National Miisemn, Vol. XVIII— No. 1054. 



195 



